On running Betaville for the first time, you will be given the option to either create a .app (OS X) or install shortcuts to your desktop and Start menu (Windows). You may use these shortcuts in confidence, as they will automatically update to the latest version of the application :)

Due to Apple's somewhat strange implementation of Java, you should ensure that you have Java 6 set as your default JVM. This is easy to do: Just go to /Applications/Utilities/Java Preferences and make sure that Java 6 is the top-most option in the displayed panel.

If you happen to run the application without this set correctly you will need to set the aforementioned property and re-run the application from the jnlp file